Shock absorber



F. E. CUSACK .SHOCK ABSORBER Feb. 16, 1937.

Fild May 9, 1936 2 Sheets-Sheet l Patented Feb. 16, 1937 FATENT OFFi 4 Claims.

This invention aims to provide a novel shock absorber, adapted to be interposed between the bull wheel and the crank shaft, in known constructions wherein the crank shaft is disposed between the bull wheel and the hole that is being formed by Well-drilling apparatus.

The invention aims to improve the construction of the shock absorber and to provide novel means for mounting and sustaining it.

It is within the province of the disclosure to improve generally and to enhance the utility of devices of that type to which the invention appertains.

With the above and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed, may be made within the scope of what is claimed, without departing from the spirit of the invention.

In the accompanying drawings:

Figure 1 shows, in side elevation a portion of a well-drilling apparatus equipped with the device forming the subject matter of this application;

Figure 2 is a longitudinal section of the shock absorber;

Figure 3 is a top plan wherein parts have been broken away;

Figure 4 is a longitudinal section of one of the braces;

Figure 5 is an elevation showing how the braces may be mounted at their lower ends.

The device forming the subject matter of this application is adapted to be used in connection with many known well-drilling machines of that general type in which the crank sets between the bull wheel and the hole that is being drilled. One form of a machine of that kind is shown in Fig. 1 of the drawings, but the invention is not confined to use with the particular machine delineated.

The numeral I marks a foundation, generally made of timber, and carrying a derrick 2. A means 3 is provided for supporting for rotation, the shaft 3 carrying the band wheel 5. A crank 6 is secured to the shaft 3. A shaft l is mounted on the crank 6, in adjusted positions longitudinally of the crank, the crank 6 being provided with means 8 whereby the aforesaid adjustment of the shaft 7 may be brought about. A grooved pulley 9 is journaled for rotation on the shaft 1. The foundation Icarries a means ID for supporting the bull wheel shaft l l for rotation, the

bull wheel being marked by the numeral 42. The line I4 is engaged around the drum of the bull wheel shaft I i and passes around the crank pulley 9, to the upper end of the derrick 2, and downwardly into the hole that is being drilled or Worked otherwise.

The parts hereinbefore described are known and common, and no novelty is claimed for them saving insofar as they may enter into combination with parts hereinafter described.

In carrying out the invention, there is provided a telescopic post I5, including a lower tubular member It having a foot plate ll secured to the foundation l, between the bull wheel i2 and the crank shaft 1. An upper tubular member it is mounted for vertical reciprocation in the lower tubular member l6 and is provided with a bottom l9. Oil may be introduced into the lower part of the lower tubular member it, to lubricate the springs hereinafter mentioned, and to facilitate the vertical sliding movement of the upper tubular member I 8. With this end in view, the lower tubular member I6 is supplied with a filling and drain plug 2!], shown in Fig. 2 of the drawings.

The lower end of a stem 2! is secured at 22 to the foot plate I1, which closes the lower end of the lower tubular member IS. The stem 2i passes slidably through the bottom is of the upper tubular member l8, and extends upwardly into the upper tubular member. A rebound spring 23, which is a compression spring, is disposed within the upper tubular member is, about a portion of the stem 2!. The lower end of the spring 23 abuts against the bottom E9 of the upper tubular member it. The upper end of the spring 23 abuts against a washer 24 on the stem 2!. A tubular spacer 25 is placed on the upper part of the stem 2|, the lower end of the spacer l engaging the washer 24. A washer 26 is mounted on the upper part of the stem 25 and engages the upper end of the spacer 25. superposed nuts 27 are threaded on the upper end of the stem 2 i, the lowermost nut engaging the washer 25. The nuts 2? constitute means for adjusting the efiort of the spring 23, in a way which will be understood readily when Fig. 2 of the drawings is noted. Parallel guide plates 28 are mounted in the upper end of the upper tubular member i8 and extend across the same. In the guide plates 28 and in the upper tubular member it, a shaft 29 is mounted. A grooved pulley 38 is journaled on the shaft29 and operates between the guide plates 28. The line H passes along the tread of owing to the presence of the oil in the lower post against the foot plate H.

therefore, support it for vertical yielding movement.

Longitudinally adjustable braces 33 are provided. Each brace 33 includes a lower outer tubular member 3 provided at its lower end with a reduced fin 35 connected by an attaching element 36 to an car 31 at the end of an anchor strip 138 secured to the foundation I. An upper tubular member 39 has limited movement in the lower or outer tubular member 3 40f each brace 33. The ends of a cross boltor stop 43 are mounted in the lower member 34 of each brace, near to the upper end of the said member. Each upper tubular member 39 has oppositely disposed elongated longitudinal slots 6|, through which the stops ib pass, relative longitudinal movement between the members 39 and 34 of the brace thus being possible. An abutment pin i2 is mounted in the upper tubular brace member 39, above the.

lower brace member '34. A washer 43 surrounds the'upper tubular member 33 and abuts against the pin 42. A compression spring 4d surrounds a portion of the upper tubular brace member 39. The upper end of the spring 44 engages the washer 43, and the lower end of the compression springs engages a washer 45 mounted on the upper tubular member 39 and having a bearing on the upper end of the lower tubular member 34. Connectors 45 are threaded for adjustment into the upper ends of the parts 39 of the braces 33 and are held in adjusted positions by superposed nuts il threaded on the connectors 45, the lowermost of the said nuts engaging the upper ends of the brace members 39. The connectors 46 have flattened ends 48 connected lay-attaching elements 49 with oifset'brackets 58 carried by the lower member l6 of the post, near tothe upper end of the said member.

Without extended explanation, and simply by an examination of Fig. 2 of the drawings, it will be obvious that the upper tubular member l8 of the post ib can move downwardly with respect to the lower member it of the post, responsive to downward pressure exerted by the line is on-the pulley 36 that is carried by the upper portion of the post.

by the springs 32 and 3!, and any rebound that jump out of the grooved pulley 3B. The inclined braces 33 are adjustable for length, by rotating the connectors 35 and by holding them in ad-' adapted to'withstand long continued and hard" se, without expert attention. ,Wear is cut down,

The downward movement of the upper portion iii of the post is checked yieldably member 16. If an operator is caught in any of the working parts, the device forming thesubject matter of this application will prevent him from V I being subjected to serious injury.

I'he device is easily setup and saves time in' hooking on, to start spudding. The number of working parts is cut down to a minimum, and wear and cost of material is decreasedaccordingly. Should the springs 3| or 32 break, they will still be held in position and will continue, to a considerable degree, to exercise their function.

There is practically no limit to the depth of the hole that can be drilled or worked upon when a drilling rnachine is equipped with the device.

forming the subject matter of this application.

The structure will operate in a satisfactory way' in connection with any standard machine in e which the crank is locatedbetween the bull wheel the utility of the telescopic braces 33 and the springs as will be appreciated readily.

Having thus described the invention, what is claimed is: a

1. In a well-drilling mechanism, a bull wheel shaft and a crank member spaced from the bull wheel shaft, a line extending from the bull-wheel "raft across the crank member, and a shock absorber mounted between the bull wheelshaft and the crank member and comprising a resiliently' supported part across which the line passes.

2. In a well-drilling mechanism, a bull wheel shaft a crank memberspaced from the 'bull Wheel shaft, a' line extended from the bull wheel shaft across the crank member, a telescopic post mounted between the bull wheel shaft and the crank member and comprising upper and lower pcrtions, means for supporting the upper portion of the post yielclably, and means carried by the upper portion of the post for engaging theline at a place between the bullwheel shaft and the ing a line, resilient means for urging the upper member upwardly, a brace'having its. upper end connected to the lower member of the post, the q brace comprising parts having relative'longitudinal movement with respect to each other, spring means for limiting said movement of the parts of the brace, and means for adjusting the length of 7 V the brace.

hln a welld-rilling mechanism, a shock absorber comprising telescopically connected upper to the lower member andextending upwardly into the upper said'member, a first compression spring about the stem and interposed between ting against the lowe'r end of the upper member,

and an abutment on the stem and engaging the the lower end of the lower member and the lower a end of the upper member, a second compression spring about the stem and disposed in the upper member, the lower end of thesecond spring abutv 

